Bit twiddling builtins

[Richard Henderson]

On Wed, Jan 29, 2003 at 02:28:02AM +0100, Falk Hueffner wrote:
> the patch is mostly finished now, only I was trying to convert
> 
> 	(ctz:narrow x)
> to
> 	(if_then_else x (ctz:wide (zero_extend:wide x)) (width narrow))

I'll look at the rest later, but... why?  The clz transformation
doesn't need an if_then_else.  An unconditional subtract works fine.

Plus, it should definitely be undefined at zero (since everyone 
does this differently).


r~